The continuous influx of opioid compounds into aquatic environments has become an increasing and persistent concern, due to their extensive use. This is especially alarming as wastewater treatment plants (WWTPs) are unable to completely remove them. Despite the reported health concerns, the occurrence of opioid compounds in the environment has not received much attention. The present study investigates the occurrence of 19 opioids in four WWTPs and their respective receiving water bodies. All wastewater samples revealed opioids at concentration ranging from ng/L to μg/L with most influents having higher concentrations than effluents. WWTPs appeared to perform poorly (p > 0.05 between influents and effluents), and were unable to remove some opioids including Methadone (−27.3%) from the Leeuwkuil WWTP, Codeine (−21.7%) and Thebaine (−3.77%) from the Sandspruit WWTP, and Hydrocodone (−1.06%) from the Meyerton WWTP, respectively. Samples collected from the Leeuwkuil WWTP were the most contaminated, with eighteen out of nineteen opioid analogues exceeding 1 μg/L. Upstream surface water contained less opioids (most < LOQ) than downstream (p < 0.05), with Hydrocodone, Oxycodone, Hydromorphone, Fentanyl, Ketamine and Dihydrocodeine not detected. The occurrence of high concentrations of opioid analogues in downstream surface water (298 ng/L −10.8 μg/L for Klip River, 4.49 ng/L −13.1 μg/L for Vaal River, 70.5 ng/L −10.0 μg/L for Soutspruit River and 8.0 ng/L – 2.43 μg/L for Sun Spruit River) was directly linked to their mass loads in the respective wastewater effluent samples.

Elevated levels of particulate matter (PM) in urban atmospheres are one of the major environmental challenges of the Anthropocene. To effectively lower those levels, identification and quantification of sources of PM is required. Biomonitoring methods are helpful tools to tackle this problem but have not been fully established yet. An example is the sampling and subsequent analysis of spider webs to whose adhesive surface dust particles can attach. For a methodical inspection, webs of orb-weaving spiders were sampled repeatedly from 2016 to 2018 at 22 locations in the city of Jena, Germany. Contents of Ag, Al, As, B, Ba, Ca, Cd, Co, Cr, Cs, Cu, Fe, K, La, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, S, Sb, Si, Sn, Sr, Th, Ti, V, Y, Zn and Zr were determined in the samples using inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) after aqua regia digestion.Multivariate statistical methods were applied for a detailed evaluation. A combination of cluster analysis and principal component analysis allows for the clear identification of three main sources in the study area: brake wear from car traffic, abrasion of tram/train tracks and particles of geogenic origin. Quantitative source contributions reveal that high amounts of most of the metals are derived from a combination of brake wear and geogenic particles, the latter of which are likely resuspended by moving vehicles. This emphasizes the importance of non-exhaust particles connected to road traffic.Once a source identification has been performed for an area of interest, classification models can be applied to assess air quality for further samples from within the whole study area, offering a tool for air quality assessment. The general validity of this approach is demonstrated using samples from other locations.

PM₂.₅ has a major impact on the gastrointestinal system, but the specific mechanism behind this action is not fully understood. Current studies have focused on the relationship between PM₂.₅ and intestinal flora disorder, while ignoring the important influence of diet on gut microbes. In this study, SD rats were fed either a normal, high-fat, or high-carbohydrate diet for two months and exposed to PM₂.₅ (7 mg/kg b.w.) by intratracheal instillation. The results showed that the body and kidney weights of the rats in the high-fat diet group were significantly increased relative to those with a normal diet, and changes in the intestinal microbes and metabolites induced by PM₂.₅ were observed. Rats in the high-carbohydrate diet group had a significant response, and the diversity and richness indices of the flora were reduced (p < 0.05); additionally, intestinal Biffidobacterium and Lactobacillus were enriched, while many endogenous metabolites were found. Some amino acids derivatives and long-chain fatty acids were increased (p < 0.05). Both diet structure and PM₂.₅ exposure can affect the composition of gut microbiota, and intestinal metabolites may be associated with cell membrane damage when a high-carbohydrate diet interacts with PM₂.₅. This study considers multiple dietary factors to further supplement the evidence of intestinal damage via PM₂.₅.

The study of emissions and depositions of atmospheric reactive nitrogen species (Nᵣs) in a region is important to uncover the sources and sinks of atmospheric Nᵣs in the region. In this study, atmospheric total Nᵣs depositions including both wet-only and dry deposition were monitored simultaneously across major land-use types in a 105 km² catchment called Jinjing River Catchment (JRC) in subtropical central China from 2015 to 2016. Based on activity data and emission factors for the main Nᵣs emission sources, ammonia (NH₃) and nitrogen oxides (NOₓ) emission inventories for the catchment were also compiled. The estimated total Nᵣs deposition in JRC was 35.9 kg N ha⁻¹ yr⁻¹, with approximately 49.7 % attributed to reduced compounds (NHₓ), and 40.5 % attributed to oxidized (NOy). The total Nᵣs emission rate in JRC was 80.4 kg N ha⁻¹ yr⁻¹, with 61.5 and 18.9 kg N ha⁻¹ yr⁻¹ from NH₃ and NOₓ emissions, respectively. Livestock excretion and fertilization were the two main contributing emission sources for NH₃, while vehicle sources contributed the bulk of NOₓ emissions. The net atmospheric budgets of Nᵣs in paddy field, forest, and tea field were +3.7, −36.1, and +23.8 kg N ha⁻¹ yr⁻¹, respectively. At the catchment scale, the net atmospheric budget of Nᵣs was +47.7 kg N ha⁻¹ yr⁻¹, with +43.7 kg N ha⁻¹ yr⁻¹ of NHₓ and +4.0 kg N ha⁻¹ yr⁻¹ of NOy, indicating that the subtropical catchment was net sources of atmospheric Nᵣs. Considering that excessive atmospheric Nᵣ emissions and deposition may cause adverse effects on the environment, effects should be conducted to mitigate the Nᵣs emissions from agriculture and transportation, and increasing the area of forest is good for reducing the net positive budget of atmospheric Nᵣs in the subtropical catchments in China.

Emerging per-/polyfluoroalkyl substances (PFASs), such as chlorinated polyfluorinated ether sulfonates (Cl-PFESAs), have been detected in human samples, yet investigation on their occurrence in pregnant women remains limited. Herein, ten legacy PFASs, branched perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), two Cl-PFESAs, perfluoro-2-propoxypropanoic acid (HFPO-DA), and ammonium 4,8-dioxa-3H-perfluorononanoate (ADONA) were detected in serum samples from 480 pregnant women in Tianjin, China. The influencing effects of age, body mass index, gravidity, and parity were also evaluated. PFOS [geographic mean (GM): 7.05 ng/mL], 6:2Cl-PFESA (GM: 5.31 ng/mL), and PFOA (GM: 2.82 ng/mL) were the dominant PFASs in the serum of pregnant women, while neither HFPO-DA nor ADONA was detectable in any serum. The serum concentration of Cl-PFESAs and 6:2Cl-PFESA/PFOS ratio in the present study were 2–5 times higher than that in previous studies of pregnant women in China. Serum concentrations of Cl-PFESAs were significantly correlated with all detected PFAAs (Spearman’s Rho: 0.15–0.69, p < 0.01) excepting perfluoropentanesulfonate (PFPeS), indicating common exposure sources for Cl-PFESAs and PFAAs and some particular exposure source for PFPeS. Younger age and multi-parity were associated with lower serum concentrations of PFOS and several perfluoroalkyl sulfonates but not associated with Cl-PFESAs or PFOA, suggesting an increasing exposure to Cl-PFESAs and PFOA which neutralized the impact of age and parity. Overall, this study indicated a relatively high exposure level and composition of 6:2Cl-PFESA in pregnant women in the north coast of China, which highlights the need to investigate the exposure sources in this area.

Since humans spend more than 90% of their time in indoor environments, indoor exposure can be an important non-dietary pathway to hazardous organic contaminants. It is thus important to characterize the chemical composition of indoor dust to assess the total contaminant exposure and estimate human health risks. The aim of this investigation was to perform a comprehensive chemical characterization of indoor dust. First, the robustness of an adopted extraction method using ultrasonication was evaluated for 85 target compounds. Thereafter, a workflow combining target analysis, suspect screening analysis (SSA) and nontarget analysis (NTA) was applied to dust samples from different indoor environments. Chemical analysis was performed using both gas chromatography and liquid chromatography coupled with high resolution mass spectrometry. Although suppressing matrix effects were prominent, target analysis enabled the quantification of organophosphate/brominated flame retardants (OPFRs/BFRs), liquid crystal monomers (LCMs), toluene diisocyanate, bisphenols, pesticides and tributyl citrate. The SSA confirmed the presence of OPFRs but also enabled the detection of polyethylene glycols (PEGs) and phthalates/parabens. The combination of hierarchical cluster analysis and scaled mass defect plots in the NTA workflow confirmed the presence of the above mentioned compounds, as well as detect other contaminants such as tetrabromobisphenol A, triclocarban, diclofenac and 3,5,6-trichloro-2-pyridinol, which were further confirmed using pure standards.

In order to study the co-existing environment of pests and economic animals, the toxicity of 15 insecticides to Plutella xylostella, Monopterus albus, and Paramisgurnus dabryanus was tested. Combined with the recommended maximum doses in the field and bioassay, the results showed that for the three insecticides that were of relatively low toxicity to M. albus and P. dabryanus, spinetoram showed the best control effect on P. xylostella, followed by chlorfenapyr and chlorantraniliprole. However, P. xylostella showed a relatively high resistance to chlorfenapyr. Therefore, the best insecticide suitable for the fields with the cauliflower-finless eel or cauliflower-loach planting and rearing combination was spinetoram, followed by chlorantraniliprole and chlorfenapyr. Other insecticides such as emamectin benzoate, Bacillus thuringiensis (Bt), matrine, and so on were effective against the diamondback moth, but they were not suitable for use because of their high toxicity to the finless eel and loach.

Air pollution could be a risk factor for the development of pterygium. This study aimed to investigate the potential associations between outpatient visits for pterygium and air pollutants. Using a time-stratified case-crossover design, the data of 3017 outpatients with pterygium visiting an eye center in Hangzhou, China, and the air pollution data of the Environmental Protection Department of Zhejiang Province between July 1, 2014, and November 30, 2019, were examined. The relationships between the air pollutants nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone, and fine particulate matter (PM) with median aerometric diameter <2.5 μm (PM₂.₅) and <10 μm (PM₁₀) and outpatient visits for primary pterygium were assessed using single- and multiple-pollutant models. Significant associations between outpatient visits for pterygium and air pollutants (PM₂.₅, PM₁₀, SO₂, and NO₂) were observed. Younger patients were found to be more sensitive to air pollution. Interestingly, the younger female patients with pterygium were more vulnerable to PM₂.₅ exposure during the warm season, while the younger male patients with pterygium were more sensitive to NO₂ during the cold season. Significant effects were also observed between the pterygium outpatients and PM₂.₅ (odds ratio [OR] = 1.06, P = 0.02), PM₁₀ (OR = 1.04, P = 0.01), and SO₂ (OR = 1.26, P = 0.01) during the warm season, as well as NO₂ (OR = 1.06, P = 0.01) during the cold season. Our study provides evidence that outpatient visits for pterygium are positively associated with increases in the air pollutants PM₂.₅, PM₁₀, SO₂, and NO₂, revealing the important role of air pollution in the occurrence and development of pterygium.

Volatile organic compounds (VOCs) are important precursors of photochemical pollution. However, a substantial fraction of VOCs, namely, oxygenated VOCs (OVOCs), have not been sufficiently characterized to evaluate their sources in air pollution in China. In this study, a total of 119 VOCs, including 60 OVOCs in particular, were monitored to provide a more comprehensive picture based on different online measurement techniques, proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS) and online gas chromatography/mass spectrometry (GC/MS), at a receptor site in southeastern China during a photochemically active period. Positive matrix factorization (PMF) and photochemical age-based parameterization were combined to identify and quantify different sources of major VOCs during daytime hours, with the advantage of including VOC decay processes. The results revealed the unexpected role of biomass burning (21%) in terms of ozone (O₃) formation potential (OFP) when including the contributions of OVOCs and large contributions (30–32%) of biomass burning to aldehydes, as more OVOCs were measured in this study. We argue that biomass burning could significantly enhance the continental atmospheric oxidizing capacity, in addition to the well-recognized contributions of primary pollutants, which should be seriously considered in photochemical models and air pollution control strategies.

Air quality forecasting for Hong Kong is a challenge. Even taking the advantages of auto-regressive integrated moving average and some state-of-the-art numerical models, a recently-developed hybrid method for one-day (two- and three-day) ahead forecasting performs similarly to (slightly better than) a simple persistence forecasting. Long-term forecasting also remains an important issue, especially for policy decision for better control of air pollution and for evaluation of the long-term impacts on public health. Given the well-recognized negative effects of PM₂.₅, NO₂ and O₃ on public health, we study their time series under the multi-scale framework with empirical mode decomposition and nonstationary oscillation resampling to explore the possibility of long-term forecasting and to improve short-term forecasts in Hong Kong. Applied to a dataset from January 2016 to December 2018, the long-term forecasting (with lead time about 100 days) of the multi-scale framework has the root-mean-square error (RMSE) comparable with that of the short-term (with lead time of one or two days) forecasting by the persistence method, while its improvement for short-term forecasting (with lead time of one, two or three days) is quite substantial over the persistence forecasting, with RMSEs reduced by respectively 44%–47%, 30%–45%, and 40%–60% for PM₂.₅, NO₂, and O₃. Compared to the hybrid method, it turns out that, for short-term forecasting for the same data, the multi-scale framework can reduce RMSE by about 25% (respectively 30%) for PM₂.₅ (respectively NO₂ and O₃). In addition, we find no significant difference in the forecasting performance of the multi-scale framework among different types of stations. The multi-scale framework is feasible for time series forecasting and applicable to other pollutants in other cities.